>>> good morning. a responsibility to act. president obama defends his decision to involvele the u.s. military in libya but vowed our troops will not be used to overthrow moammar gadhafi by force. >> to be blunt, we went down that road in iraq. >> did the president say enough to quiet his critics? >> prince harry joins a punishing expedition to the north pole. we are with him live. >> and buried. a snow boarder crashes and becomes trapped upside down in six feet of snow. his helmet camera captured it all including a desperate call to his wife. >> i'm stuck in a tree well. give them my phone number. >> are you serious? >> i'm going to die if they don't find me. >> luckily, she did and he was finally rescued. he's sharing his story with us finally rescued. he's sharing his story with us today, tuesday, march 29, 2011. captions paid for by nbc-universal television >>> welcome to "today" on this tuesday morning. i'm meredith vieira. >> i'm matt lauer. president obama vowed america's role would be limited in libya last night. he told the nation we had fulfilled the pledge, we had done wha